This application a third 5-year period for a program project having the following general goals: (1) to assess the utility of approaches, instrumentation, and neurophysiological analysis procedures designed to enable the identification and quantification of central somatosensory nervous processes in normal subjects and patient populations experiencing a variety of chronic orofacial sensory disorders; and (2) to evaluate experimentally the hypothesis that in a variety of orofacial sensory disorders, which are associated with certain types of temporomandibular disorders or which result from damage to the trigeminal nerves, occur as a consequence of abnormalities in the dynamic integration of sensory information by peripheral and central nervous system substrates that respond to noxious and non-noxious somatosensory stimuli. The skills, prior experiences, and interests of the investigative team is consistent with the goals proposed, and collectively, the assembled research team possesses a considerable record of contributions to somatosensory physiology and human psychophysics, and includes appropriate expertise in the evaluation management, and treatment of clinical pain populations. The Program involves four interactive scientific projects, ill interactive with a Core designed to: (1) provide the number of carefully screened and characterized human subjects and patients required to satisfy each subproject's specific aims; (2) make available to each subproject high quality and targeted statistical consultation; (3) stimulate sharing and integration the information obtained by the different projects and the interpretation of that information in terms of the neural mechanisms underlying chronic orofacial sensory disorders, and finally; (4) provide essential administrative support, coordination, and scientific leadership.